Olive refuses to pee outside when it’s cold and dark, then goes on the rug

It gets dark around 5:30 now and it’s cold here in Dearborn. I stand on the porch in my big coat for ten minutes while Olive sniffs everything except the grass. We go back inside, I turn around to find my youngest, and there’s a puddle by the rug. My kids think it’s hilarious. I do not. She’s 5 months old and was doing so well in September. Is this normal or did I mess something up?